After the Restoration, negotiations were in train during a series of years for a modification of the provisions of the Concordat of 1801. A series of controversial publications bearing upon the Concordat were placed upon the Index as they appeared. Constant, Benjamin, _De la Religion Considerée dans sa Source_, etc., printed in 1824–1831, in five volumes, prohibited in 1827. Gandolphy, Peter, _A Defence of the Ancient Faith, or Exposition of the Christian Religion_, printed (in London) in 1813, prohibited in 1818. Gandolphy was a priest of the Catholic Church and at the time of this publication had charge of the Spanish Chapel in London. The book had been promptly condemned by Pointer, Apostolic Vicar in London. Gandolphy journeyed to Rome and succeeded in securing for his book the approval of the master of the palace and a certificate giving him the authority to state that his book had been approved by the Holy See. On the strength of this certificate, he placed copies again on sale. Pointer secured from the Inquisition instructions to confirm the prohibition, and as this was still ignored by Gandolphy, the latter was suspended. After some years of controversy, the difficulty was finally adjusted by the correction of the text according to the specifications of Pointer. Earle, Charles J., _The Forty Days, or Christ between His Resurrection and Ascension_ and _The Spiritual Body_. These were printed in 1876 and 1878 and were prohibited in 1880. Earle had in 1851 been converted to Romanism. In 1857, an association was instituted in England “for the promotion of the unity of Christendom.” Its special purpose was to bring together the members of the Catholic, the Greek, and the English Churches. The members of the society accepted the obligation to make a daily prayer to this end. Cardinal Patrizzi declared in the name of the Inquisition, in a letter addressed, September, 1864, to the English bishops, that Catholics were forbidden to take part in this association. In 1866, Archbishop Manning confirmed this prohibition. Patrizzi had condemned in his first letter the _Union Review_, which was the organ of the society, but the _Review_ was not placed on the Index. A series of essays on the reunion of Christendom, written by members of the society, and edited by F. G. Lee, was placed on the Index in 1867.